For 10 years, researchers tracked a nocturnal forager between Europe and Africa.
They discovered a life governed by a lunar calendar.
This species synchronizes its hunting, migration, and breeding seasons almost entirely with the glow of the Moon.
When moonlight fades, the birds enter a form of torpor to survive.
This discovery reveals how a natural, silent clock overhead dictates the survival and rhythm of nocturnal life.
How does moonlight have anything to do with avian survival?
What a 10-year study revealed about the moon’s grip on this “werewolf” species
Researchers tracked the bird between southern Europe and West Africa.
The project stretched across multiple migration cycles.
Tiny tracking devices recorded patterns in movement, feeding, and flight activity.
The bird, a member of the Caprimulgidae family, grew noticeably more active during brighter lunar phases.
On darker nights, behavior shifted to energy conservation.
Flights became shorter.
Hunting trips dropped sharply.
Researchers noticed the bird often delayed longer movements until moonlight returned.
This led scientists to investigate energy use rather than just navigation.
Scientists realized the Moon influenced more than navigation alone.
It affected the bird’s energy use.
The bird responded by conserving energy instead.
Researchers later connected the same rhythm to migration timing.
The pattern appeared again during nesting seasons.
Eggs often hatched during periods with stronger nighttime feeding conditions.
The birds had a high gizzard capacity during moonlit windows, so they “binge ate.”
That gave chicks better access to food immediately after hatching.
Hatching is timed to the full moon so parents can hunt longer to feed chicks
Why the bird’s yearly cycle appears linked to light pollution
Unlike bats, the bird cannot fully rely on echolocation.
Researchers discovered it relies on vision, which is why moonlight is a requirement, not a preference.
When moonlight brightened the landscape, insect activity increased dramatically.
The bird reacted almost immediately.
Tracking devices recorded longer flights and extended hunting periods.
During darker nights, activity dropped again.
The Moon effectively became a natural schedule.
Researchers also noticed migration routes shifting alongside lunar brightness.
Brighter nights created safer travel conditions.
That allowed the bird to wait for the specific energy balance (two weeks after a full moon) to begin the journey.
The same cycle repeated across multiple years.
Scientists now believe natural light cycles still shape many nocturnal species.
Even small changes in nighttime brightness can alter feeding behavior.
The concern is growing and has been detailed by the study, “Moonlight drives the energy balance and annual cycle of a nocturnal forager,” published in Science.
The findings have also been backed by a report from Lund University.
The high cost of artificial light
The bird in question was the Red-necked Nightjar.
It’s a nocturnal species known for its almost silent rattling calls after sunset.
It can be found in Europe and Africa for the most part.
Researchers discovered the species synchronizes major life activities with lunar cycles.
Moonlight directly affects how it survives.
The study showed brighter nights extend hunting opportunities for hours.
That extra feeding time provides critical energy reserves.
Those reserves help power migrations across continents.
Researchers also discovered that the lunar cycle influences breeding timing.
Eggs often hatch during brighter periods with improved feeding conditions.
A species living by moonlight
The discovery may also explain similar behavior seen in other migratory species.
Researchers have already observed moon-related changes in seabirds and skylarks.
The night sky may guide far more wildlife than expected.
For a species that treats the Moon as a survival calendar, light pollution isn’t just a nuisance.
It’s a biological “desync.”
This bird’s internal clock tells it to hunt or migrate based on specific light levels.
City glows create a permanent, artificial full moon.
This disrupts the energy-saving torpor they rely on during dark phases.
And it forces them to “run” on empty.
By altering the night sky, we are dismantling a timing system shaped over millions of years.
For animals already operating near their energy limits, even subtle disruptions could matter.
For some species, it quietly controls life itself.